Electrographic forms print station

ABSTRACT

An electrographic printing device is provided with a forms print station including an electrode drum having forms information raised thereon which operates on a dielectric print medium. The forms print station provides means for the rapid printing of various size forms on the print medium which are then transported through the electrographic printing device for the addition of variable information at a print station downstream thereof.

United States Patent 11 1 Borelli 1 1 May 28, 1974 1 1 ELECTROGRAPHIC FORMS PRINT STATION [75] Inventor: Ronald F. Borelli, Edmond, Okla.

[73] Assignee: Honeywell Information Systems Inc.,

Waltham, Mass.

22 Filed: 15H. 2 ,1573

[21] Appl. No.: 320,419

[52] US. Cl 101/216, 101/DIG. 13, 101/92,

118/637, 101/375 [51] Int. Cl B411 5/00 [58] Field of Search 101/D1G 13, 375, 426,

101/93 C, 212, 216, 92; 118/637, 638, DIG 15; 346/74, 74 ES; 117/175, 37, 37 LE [56] References Cited UNITED STATES PATENTS 1,442,287 1/1923 Mattern 101/216 2,901,374 8/1959 Gundlach 101/D1G. 13

2,9721'2'97" 2/1961 Auerbacher..... 101/426 x 3,046,877 7/1962 Janke mm c x 3,198,648 8/1965 Trimbur 10l/D1G. 13

3,203,345 8/1965 3,383,697 5/1968 3,414,723 12/1968 3,532,054 10/1970 Zaphiropoulos 10l/D1G. 13 3,697,268 10/1972 Wasaburo Ohta 101/D1G. 13 3,701,337 lO/1972 Borelli l0l/D1G. 13

Primary Examiner-Robert E. Pulfrey Assistant ExaminerE. H. Eickholt Attorney, Agent, or Firm--Aubrey Brine; Gerald R.

Woods [57] ABSTRACT An electrographic printing device is provided with a forms print station including an electrode drum having forms information raised thereon which operates on a dielectric print medium. The forms print station provides means for the rapid printing of various size forms on the print medium which are then transported through the electrographic printing device for the addition of variable information at a print station downstream thereof.

9 Claims, 8 Drawing Figures MTENTEDmzs m I 3312.780

' SHEET 2 BF 2 44 4s TONER r46 40 DEVELOPER DRYER 1 ELECTROGRAPIIIC FORMS PRINT STATION BACKGROUND OF THE INVENTION 3,624,661 to Shebanow and Borelli which is assigned to the assignee of the present invention. However, it

I has been found that in practice many such data processing installations employ standard forms of one type or another, on which the variable information retrieved from the data processor is to be printed. In such installations it becomes necessary, as a matter of routine, to transfer the information from the data processing printout to the desired forms by a secondary operation, which is both time consuming and costly. One might suggest as a solution to this problem that the forms be pre-printed on the rolls of paper in the printer, for use when particular forms are to be employed. However, this becomes relatively difficult when employing electrographic printing media, which is generally a dielectric coated electrographic paper. In many instances the 'paper must be kept in a controlled environment prior to its use in the electrographic printing device and in any instance, the changing of rolls of paper to provide various form sizes and form types would require lengthly shut down of the machine and a large storage area for the various forms to be used, if stored in paper rolls.

Another requirement often expressed by the user is that the forms be of various colors contrasting with the black and white printout of the variable information of the form. Thus, the problem of providing the variable information from an electrostatic printing device onto standard forms of various sizes, types and colors, is one of extreme importance to the manufacture of present day printers of this type.

The present invention therefore, has an object to provide an electrographic printing device having a forms print station which provides forms of various sizes for subsequent printing of variable information thereon.

Another object of the invention is to provide a forms print station in combination with an electrographic printer which will provide forms of differing color than the variable print produced in the variable printing operation.

A third object of the present invention is to provide printed forms in an electrographic printing apparatus which are inexpensively produced, according to user need.

SUMMARY OF THE INVENTION upstream of the variable print station. The forms print station is provided with a pair of arms, pivotably supported in spaced relation one with the other, on which a forms drum is supported. The forms drum is biased towards an insulated back-up roller, and conductive means is provided adjacent the insulated roller for forming the electrostatic charge between the forms drum and the conductive means to thereby deposit a charge on the dielectric surface of the print medium. By applying a voltage to the forms drum, a difference in potential is produced between the conductive means and the drum, which potential difference is effective to cause printing on the dielectric medium.

A separate toner station may be provided between the forms station and the variable printing station to preprint the forms prior to depositing the variable electrostatic charge patterns thereon, and to thus produce forms which may be of contrasting color with that of the variable printing to be provided thereon.

BRIEF DESCRIPTION OF THE DRAWING The various objects of the invention together with the features and advantages thereof will become apparent from the following detailed description of a preferred embodiment, taken in connection with the accompanying drawing, wherein:

FIG. 1 is a perspective elevational view showing a print drum employed in the forms station according to v the present invention;

FIG. 2 is an elevational view of the print drum of FIG. 1 as employed in the forms station showing details of construction;

FIG. 2a is an end elevational view showing the print drum of FIG. I employed in the forms station;

FIG. 3 is a schematic view of a forms station according to the teachings of the present invention;

FIG. 4 is a schematic view of an electrographic printing device having the invention embodied therein;

FIG. 5 is an elevational view showing details of the forms station and modifications of the print drum;

FIG. 6 is an elevational view similar to FIG. 2 showing an alternate embodiment of a print drum arrangement as employed in the forms station; and

FIG. 7 is an elevational view similar to FIGS. 2 and 6 showing a modified forms drum employed in the forms station of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, and in particular to FIGS. 1, 2 and 2a, there is shown an arrangement of elements for printing forms of various dimensions which is to be included in the forms station according to the present invention. As to theory of operation, the arrangement makes use of conventional electrographic printing techniques and includes an image generator in.

the form of a metal conductive drum 10 on which is formed the image of the desired forms to be printed. The lines, or alphanumeric characters may be formed on the drum by photoetching or other metal working techniques. As shown, the characters to be imaged are in the form of raised portions 12 which extend from a recessed portion 14 of the drum 10.

In the structure described, the forms drum 10 is manufactured by photoetching a light weight cylindrical magnesium sleeve using an artwork which reflects the image of the desired form. The photoetching of the cylinder results in the desired forms image raised 10/ l ,000ths of an inch or greater above the etched out recessed portion 14, which becomes the background of the printed form. In addition to forming the raised portions 12 of the image pattern, the network is designed to form a pair of narrow rings 16 and M3 at opposite ends of the drum 10.

Referring to FIG. 2, the rings 16 and 18 of the drum 10, when located in the forms station, contacts a backup roller 20 which is a cylinder of rubber or other insulating material. The electrographic medium M is wrapped around the back-up roller 20 with the conductive side of the medium in contact with he roller. As

.also shown, in practice the drum i is spring biased against the roller 20 with the electrographic print medium M disposed therebetween.

Referring now to FlG. 3, the forms drum l0 and the back-up roller 20 is shown in a schematic presentation of a forms station according to the present invention. The drum is seen to be supported for rotation by a pair of support arms 22 and 24 which are pivotably connected to the printer structure 26. A spring 28 attached between the structure 26 and at least one of the arms 22, 24 serves to bias the drum 10 toward the roller which is fixedly attached to the structure 26.

The biasing force is generally of a value which would cause the surface of the roller 20 to be depressed in the order of3 to 4 thousandths of an inch by the raised portions 12, if the electrographic medium M were removed from between the drum 10 and the roller 20. A pair of elongated rods 30 and 32 are connected to a voltage source V and are disposed along the path of the print medium M at a location adjacent the roller 20 parallel to and in close proximity with the forms drum 10 but on the opposite side of the dielectric medium M. Thus, the dielectric medium M in its controlled movement through the apparatus passes over the rods 30 and 32 with the conductive side of the medium passing over the rods and the dielectric side of the medium passing over the forms drum 10. The forms drum 10 is likewise connected to a voltage indicated as V2, which may be applied to the drum by commutating brushes, or other means as well known in the art.

The location of forms station of FIG. 3 in the electrographic printing apparatus is best depicted from the schematic view shown in FIG. 4. The dielectric medium M is stored on a roll 34 which is contained in the machine to provide for continuous operation of the electrographic printing process. The medium M, according to the present invention and as alluded to above, is a plane surface electrographic medium such as is known in the art, having a dielectric side and an opposite con ductive side for receiving and retaining an electrostatic charge which is later developed into electrographic printing. The forms station, which is here depicted as the forms drum 10, the back-up roller 20 and the rods 30 and 32, is located downstream of the electrographic paper supply but prior to any other device for operating on the medium M.

Immediately after the forms station, a toner developer and dryer station 36 is located, such that the forms information is developed on the electrostatic medium prior to its receiving the variable information. The toner developer and dryer station 36 may include any type of such devices well known in the art or preferably may be of the type shown in U.S. Pat. Nos. 3,687,107. and 3,701,337 to Borelli et al., which are assigned to the assignee of the present invention. As a complete discussion of the elements and operation of such devices is to be found in these references, no further discussion of such is deemed necessary for an understand ing of the present invention.

From the combination toner developer-dryer station 36, the electrographic medium passes over a roller 38 and to the print station 44. From the print station 44 where variable infonnation is provided to the forms, the medium M passes through a second tonerdeveloper-dryer station 46, which may be of the same type and design as station 36, and through a pair of driver rollers 40 and 42 which serve to move the medium through the apparatus.

The print station 44 is of the type which receives variable information from a data processor or other equipment, and through selective charging of a plurality of electrodes or excitation means disposed in a print head 43, generates alphanumeric characters or other variable printing by electrostatic discharge onto the me dium M. The details of the print station 44 have not been shown herein, however, the specific elements of such a device together with an explanation of its operation are shown and described in U.S. Pat. No. 3,624,661 to Shebanow et al., and therefore further discussion of the device is not deemed to be necessary for a complete description of the present invention.

ln operation, with the medium M being fed from the supply roller 34 through the various stations described and shown in FIG. 4 and with the forms drum l0 biased against the back-up roller 20 as shown in FIG. 3, the conductive side of the electrostatic medium is in contact with the two conductive rods 30 and 32 located on both sides, and in close proximity with the rubber back-up roller 20. A relatively high potential, in the order of +700 volts, is applied at +Vl and imposed on the conducting rods 30 and 32. Prior to the printing of a form, the forms drum 10 has a +700 volt potential applied at +V2 and no printing occurs because of the existence of the same potential at either side of the dielectric medium M. Imaging is generated by switching the conductive drum from the applied 700 volts, to ground potential, causing ionization to occur between the raised characters on the drum and the conductive side of the medium M.

It should further be understood as an alternate to the aforementioned employment of energy on the drum l0 and the conducting rods 30 and 32 that the rods may be held at ground potential and the drum 10 switched from ground potential to 700 volts to achieve the same effect, that of causing ionization between the raised characters on the drum and the conductive side of the medium.

In the present arrangement, the print medium M is held taut around a section of the back-up roller 20 and the conducting rods 30 and 32, and is pulled by a drive mechanism attached to the rollers 40 and 42 forming a drive means. The medium in turn drives the roller 20 which drives the forms drum 10 by virtue of the continuous raised rings 16 and 18 being in forced frictional contact with the roller 20 at each end of the drum l0. Slippage between the drum l0 and the print medium M is thereby limited, as the medium itself is effectively turning the drum, although not in contact with it.

The forms as printed now pass through the toner developer station 36 which may contain developer, in liquid or powder form, of color other than that to be used in printing the variable information on the form. Thus,

variable colored forms may be achieved through use of the combined forms station having its own separate toner developer station 36.

The print medium M next travels through the electrographic printingapparatus wherein the variable information printed is thereon by the generation of characters at the print station 44, and subsequently developed at the developer station 46, to complete the printing process.

As previously alluded to, the present invention contemplates providing a forms station which is adaptable for various form lengths and widths. Referring to FIG. 5, it will be observed that the arms 22 and 24 which support the drum are pivotable and therefore the drum is pivotably supported such that its center of rotation is on an are A coinciding with the center of rotation of the back-up roller 20. Thus, to change the length of forms, it is only necessary to remove the drum 10 and replace it with a drum of lesser diameter, for instance as drum 10, or a drum of greater diameter as drum 10a, each of which contacts the backup roller at the same point, due to the coincident work the intersection of the arc A and roller 20. This point of contact is critical as it establishes the location of the drum 10, 100 or 10b relative to the rods 30 and 32, which remain fixed. Thus, the present structure provides means for interchanging the print drum 10 with drums of varying diameters, and therefore provides for the production of forms of varying lengths.

Referring to FIG. 7 the formation of forms having various widths is likewise easily accomplished with the present arrangement by employing the interchangable drum structure as disclosed. In that figure, a drum 100' is provided having the raised portions 12 covering only a portion of the drum. The remainder of the drum is etched to form an extended recess portion 14 which provides no printing on the medium M. The roller 10a is also provided with rings 16 and 18 formed by etching, which contact the back-up roller 20 in a similar fashion to the previously described roller 10. The roller 10d may therefore be interchanged in the printing position with any of the previous rollers described with the result that only that area of the drum having raised portions 12 produced a printed form, which is of less width than that produced by roller 10.

By using this expedient together with the use of different diameter rolls, forms of various width and length are provided, employing the same roll of print medium M, the same electrographic print structure, and without changing any other component of the forms station.

Referring to FIG. 6, there is shown an alternate embodiment of the drum l0 and roller 20 arrangement which in effect eliminates the rods 30 and 32 from the form station shown in FIGS. 3 and 4. In this alternate arrangement, the drum 10 is spring biased, as before, into pressurized contact with a back-up roll 20a which is of different construction than the back-up roll 20. In this embodiment, the roll 200 contains a center section 50 over which the dielectric medium M passes and which is fabricated of a good conductive material, such as a conductive rubber. The high voltage V which previously was indicated as being transmitted to the conductive rods 30 and 32, in this arrangement is directly transferred to the roller 20a and the cycle of printing is performed as previously described with reference to the embodiment of FIGS. 3 and 4, with the voltage V, being imposed on the roller 20a rather than on the con- 6 ductive rods 30 and 32. With this arrangement, the voltage V, is preferably a modulated DC. voltage applied through a current limiting driver to avoid arcing through areas where pin holes might exist in the dielectric coating. End caps 52 and 54 are provided at each end of the back-up roller 20a which contacts the rings 16 and 18 of the drum 10, and are fabricated of insulating material such that the drum will not short to the conductive roller.

Referring to FIG. 1, it will be noted that a pin 56 extends from at least one end of the drum l0 and rotates therewith. The pin 56 is located at the head of the form to be printed by the forms drum 10, and therefore gives an indication that a new form is initiated every time the pin 56 pases a fixed point. As shown in FIG. 4, a sensor 58 which may be a magnetic or optical device as well known in the art is disposed in the path of the pin 56 and transmits a signal to the print station 44 every time the pin 56 rotates past the fixed point at which the sensor is located. As the distance between the forms drum l0 and the print head 48 of the print station 44 is known, synchronization of the variable printing at the print head is accomplished through pulses emanating from the sensor 58 and variable information is provided in proper locations on the printed form.

From the foregoing, the reader will no doubt appreciate that the present invention provides a system of electrographic printing with the capability of printing forms of various length and 'width. The drum concept makes for ease of fabrication in that artwork can be generated by photographing an existing form and reproducing it on the surface of a relatively inexpensive drum. With the two conducting bar approach, where the rods are located a short distance away from the back-up roller, current leakage through the dielectric and arcing (which can cause inability to generate the charged image) is minimized as the proper resistance is used as current limiting.

Also, by incorporating a sensing element on the forms drum itself to sense the head of form and for synchronizing the forms printing to the variable printing, and paper cutting if present, a simplified forms station design is presented which is adaptable to most electrographic printing apparatus.

In addition, from an operators standpoint, the simplicity of changing forms by merely inserting replaceable form drums rather than an entire roll of forms in the apparatus, provides a device which is simple in operation and more flexible than present prior art electrographic printing arrangements.

What is claimed is:

1. An apparatus for providing electrographic printing on a flat flexible dielectric medium comprising driving means for moving said medium along a path, excitation means along the path for applying a latent charge to said medium in response to variable signals to form variable latent images on said medium and a forms print station located along said path upstream of said excitation means for successively forming the same latent image on said medium, said forms print station comprising roller means in frictional engagement with said medium and rotated about its axis by movement of said medium, a print drum having characters, extending from a surface thereof for forming said same latent image on each rotation of said drum which is rotatable about its axis, means for biasing said print drum toward said roller means, said drum further having ring means disposed near the ends thereof for contacting said roller means whereby said print drum is rotated by said roller means and means for applying a voltage to said drum to establish a difference of potential across the surface of said dielectric medium to produce a latent charge on the surface of said dielectric medium in the form of said print drum characters.

2. The apparatus of claim ll wherein said roller means is of an electrical insulating material and wherein said means for establishing a difference of potential across said medium comprises conductive means located adjacent said roller means and the opposite surface of said medium and a voltage source connected to said drum.

3. The apparatus of claim ll wherein said roller means is of electrical conductive material and said means for establishing a difference in potential across said medium comprises a voltage source connected to said drum.

4. The apparatus of claim 1 wherein said print drum is pivotably supported for movement of its rotational axis along an arc intersecting the rotational axis of said roller means.

5. The apparatus of claim 4 which further includes means connected to said drum for indicating the beginning of each successive same image to be formed by rotation of said drum and stationary means adjacent said drum for sensing said indicating means and providing a signal to said excitation means in response to the sensing of said indicating means.

6. An apparatus for providing electrographic printing on a flat flexible dielectric medium comprising driving means for moving said medium along a path, excitation means along the path for applying a latent charge to said medium in response to variable signals to form variable latent images on said medium, a forms print station located along said path upstream of said excitation means for successively forming the same latent image on said medium and toner developer means disposed between said excitation means and said forms print station, for developing the latent images so formed at said station, said forms print station comprising a roller fabricated of electrically insulated material in frictional engagement with said medium and rotated about its axis by movement of said medium, a print drum having characters extending from a surface thereof for forming said same latent image on each rotation of said drums which is rotatable about its axis, means biasing said print drum towards said roller, said drum further having a pair of rings extending outwardly from said surface thereof, one located adjacent either end of said drum for contacting said roller whereby said drum is rotated by movement of said roller, and means for applying a voltage to said drum to establish a difference of potential across the surface of said dielectric medium to produce a latent charge on the surface of said dielectric medium in the form of said print drum characters.

'7. The apparatus of claim 6 wherein said means for establishing a difference in potential across said medium comprises a pair of electrodes located one on either side of said roller along the path of said medium and a voltage source connected to said drum.

d. The apparatus of claim 7 wherein said print drum is pivotably supported for movement of its rotational axis along an arc intersecting the rotational axis of said roller.

9. The apparatus of claim 8 which further includes means connected to said drum for indicating the beginning of each successive same image to be formed by rotation of said drum and stationary means adjacent said drum for sensing said indicating means and providing a signal to said excitation means in response to the sensing of said indicating means. 

1. An apparatus for providing electrographic printing on a flat flexible dielectric medium comprising driving means for moving said medium along a path, excitation means along the path for applying a latent charge to said medium in response to variable signals to form variable latent images on said medium and a forms print station located along said path upstream of said excitation means for successively forming the same latent image on said medium, said forms print station comprising roller means in frictional engagement with said medium and rotated about its axis by movement of said medium, a print drum having characters, extending from a surface thereof for forming said same latent image on each rotation of said drum which is rotatable about its axis, means for biasing said print drum toward said roller means, said drum further having ring means disposed near the ends thereof for contacting said roller means whereby said print drum is rotated by said roller means and means for applying a voltage to said drum to establish a difference of potential across the surface of said dielectric medium to produce a latent charge on the surface of said dielectric medium in the form of said print drum characters.
 2. The apparatus of claim 1 wherein said roller means is of an electrical insulating material and wherein said means for establishing a difference of potential across said medium comprises conductive means located adjacent said roller means and the opposite surface of said medium and a voltage source connected to said drum.
 3. The apparatus of claim 1 wherein said roller means is of electrical conductive material and said means for establishing a difference in potential across said medium comprises a voltage source connected to said drum.
 4. The apparatus of claim 1 wherein said print drum is pivotably supported for movement of its rotational axis along an arc intersecting the rotational axis of said roller means.
 5. The apparatus of claim 4 which further includes means connected to said drum for indicating the beginning of each successive same image to be formed by rotation of said drum and stationary means adjacent said drum for sensing said indicating means and providing a signal to said excitation means in response to the sensing of said indicating means.
 6. An apparatus for providing electrographic printing on a flat flexible dielectric medium comprising driving means for moving said medium along a path, excitation means along the path for applying a latent charge to said medium in response to variable signals to form variable latent images on said medium, a forms print station located along said path upstream of said excitation means for successively forming the same latent image on said medium and toner developer means disposed between said excitation means and said forms print station, for developing the latent images so fOrmed at said station, said forms print station comprising a roller fabricated of electrically insulated material in frictional engagement with said medium and rotated about its axis by movement of said medium, a print drum having characters extending from a surface thereof for forming said same latent image on each rotation of said drums which is rotatable about its axis, means biasing said print drum towards said roller, said drum further having a pair of rings extending outwardly from said surface thereof, one located adjacent either end of said drum for contacting said roller whereby said drum is rotated by movement of said roller, and means for applying a voltage to said drum to establish a difference of potential across the surface of said dielectric medium to produce a latent charge on the surface of said dielectric medium in the form of said print drum characters.
 7. The apparatus of claim 6 wherein said means for establishing a difference in potential across said medium comprises a pair of electrodes located one on either side of said roller along the path of said medium and a voltage source connected to said drum.
 8. The apparatus of claim 7 wherein said print drum is pivotably supported for movement of its rotational axis along an arc intersecting the rotational axis of said roller.
 9. The apparatus of claim 8 which further includes means connected to said drum for indicating the beginning of each successive same image to be formed by rotation of said drum and stationary means adjacent said drum for sensing said indicating means and providing a signal to said excitation means in response to the sensing of said indicating means. 